IQ Test for 8th Graders: Quiz to Check Your Kids IQ

1. What number must be subtracted from 7 to get -7?

-14

7

1

14

Explanation

2. What is -1 times -2 times -3 times -4?

-12

12

-24

24

When multiplying negative numbers together, the product follows the rules of multiplication, but the result will be positive if there is an even number of negative factors and negative if there is an odd number of negative factors.

In this case, you have four negative numbers:

-1 * -2 * -3 * -4

Since there are four negative numbers, an even number, the product will be positive.

Now, let's calculate the product:

(-1) * (-2) * (-3) * (-4) = 24

So, -1 times -2 times -3 times -4 equals 24.

Explanation

When multiplying negative numbers together, the product follows the rules of multiplication, but the result will be positive if there is an even number of negative factors and negative if there is an odd number of negative factors.

In this case, you have four negative numbers:

-1 * -2 * -3 * -4

Since there are four negative numbers, an even number, the product will be positive.

Now, let's calculate the product:

(-1) * (-2) * (-3) * (-4) = 24

So, -1 times -2 times -3 times -4 equals 24.

3. What is the length of a line segment with endpoints at (1, 3) and (4, 3)?

1 Unit

2 Units

3 Units

4 Units

Explanation

4. How many sides does a trapezoid have?

6

3

4

5

The correct answer is 4. A trapezoid is a quadrilateral, which means it has four sides. One pair of opposite sides in a trapezoid is parallel, distinguishing it from other quadrilaterals. Additionally, a trapezoid has two non-parallel sides of different lengths. This unique characteristic allows for various properties and calculations to be determined within the shape. Knowing that a trapezoid has four sides is essential for understanding its geometric properties and how it differs from other shapes.

Explanation

The correct answer is 4. A trapezoid is a quadrilateral, which means it has four sides. One pair of opposite sides in a trapezoid is parallel, distinguishing it from other quadrilaterals. Additionally, a trapezoid has two non-parallel sides of different lengths. This unique characteristic allows for various properties and calculations to be determined within the shape. Knowing that a trapezoid has four sides is essential for understanding its geometric properties and how it differs from other shapes.

5. What is the complement of a 16 degree angle?

64 Degrees

54 Degrees

74 Degrees

84 Degrees

Explanation

6. What is 37 degrees Celsius in Fahrenheit?

98.6 Degrees

100 Degrees

65 Degrees

37 Degrees

Explanation

7. What is 10 degrees Celsius in Fahrenheit?

16 Degrees

50 Degrees

34 Degrees

76 Degrees

Explanation

8. How many seconds are in 26.9 minutes?

16140

2690

1614

269

Explanation

9. What is the supplement of a 176 degree angle?

24 Degrees

14 Degrees

-4 Degrees

4 Degrees

Explanation

10. What is (3a + b)/2c if a = 3, b = 2 and c = 5?

2.2

2.4

1.1

3.3

Explanation

11. What is the absolute value of -3 - 2?

4

1

5

3

The absolute value of a number is its distance from zero on the number line, regardless of direction. To find the absolute value of -3 - 2, you first need to evaluate the expression inside the absolute value brackets:

|-3 - 2| = |-5|

Now, since -5 is 5 units away from zero on the number line, the absolute value is 5.

Therefore, the absolute value of -3 - 2 is 5.

Explanation

The absolute value of a number is its distance from zero on the number line, regardless of direction. To find the absolute value of -3 - 2, you first need to evaluate the expression inside the absolute value brackets:

|-3 - 2| = |-5|

Now, since -5 is 5 units away from zero on the number line, the absolute value is 5.

Therefore, the absolute value of -3 - 2 is 5.

12. What is true about vertical angles?

They are always congruent.

They are always 90 degrees.

They are always supplementary.

They are always complementary.

Vertical angles are formed when two lines intersect. They are the angles that are opposite each other, and they always have the same measure (meaning they are congruent). The other options are incorrect because vertical angles don't have to be 90 degrees (that's only if the lines are perpendicular), and they don't add up to 90 or 180 degrees unless the lines are perpendicular. Sources and related content

Explanation

Vertical angles are formed when two lines intersect. They are the angles that are opposite each other, and they always have the same measure (meaning they are congruent). The other options are incorrect because vertical angles don't have to be 90 degrees (that's only if the lines are perpendicular), and they don't add up to 90 or 180 degrees unless the lines are perpendicular. Sources and related content

13. What is the complement of a 76 degree angle?

14 Degrees

104 Degrees

16 Degrees

24 Degrees

Explanation

14. If 721 out of 950 people like basketball, how many of 10,000 should like basketball (rounded)?

7700

7500

7589

7210

Explanation

15. What value of x makes "8 + x = 0.8" a true statement?

-7.2

-8.800000000000001

7.2

8.800000000000001

Explanation

16. How many cc's are in 15 mL?

0.15 cc

150 cc

15 cc

1.5 cc

Explanation

17. If f(x) = 2x - 3, what is f(-3)?

-9

9

3

-3

Explanation

18. There are two children in a family, what is the probability that both are girls?

25 percent

40 percent

75 percent

100 percent

Explanation

19. What is 5 degrees Celsius in Fahrenheit?

21 Degrees

45 Degrees

41 Degrees

37 Degrees

Explanation

20. How many milliliters are in one cubic centimeters?

1 Milliliter

2 Milliliters

10 Milliliters

1/2 Milliliter

One cubic centimeter is equal to one milliliter. This is because the volume of a cube with sides measuring one centimeter is equal to one cubic centimeter, and since one milliliter is equivalent to one cubic centimeter, the answer is 1 milliliter. Therefore, there are 1 milliliter in one cubic centimeter. This conversion is commonly used in the measurement of liquids. This conversion is particularly useful in the field of chemistry for accurately measuring and calculating volumes of liquids. It simplifies calculations and ensures precision in scientific experiments and formulations.

Explanation

One cubic centimeter is equal to one milliliter. This is because the volume of a cube with sides measuring one centimeter is equal to one cubic centimeter, and since one milliliter is equivalent to one cubic centimeter, the answer is 1 milliliter. Therefore, there are 1 milliliter in one cubic centimeter. This conversion is commonly used in the measurement of liquids. This conversion is particularly useful in the field of chemistry for accurately measuring and calculating volumes of liquids. It simplifies calculations and ensures precision in scientific experiments and formulations.

IQ Test For 8th Graders: Check Your Kids IQ